Update pitest.yml (#969)

Use only native cache

Author: pivovarit

.github/workflows/pitest.yml

@@ -26,12 +26,6 @@ jobs:
           architecture: ${{ matrix.architecture }}
           distribution: 'oracle'
 
-      - uses: actions/[email protected]
-        with:
-          path: ~/.m2/repository
-          key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}
-          restore-keys: ${{ runner.os }}-maven-
-
       - name: Run Mutation Testing
         run: mvn package -Ppitest org.pitest:pitest-maven:mutationCoverage